The Full form of PPI is Proton Pump Inhibitors. PPIs are a group of drugs whose main action is a pronounced and long-lasting reduction of stomach acid production. Within the class of medications, there is no clear evidence that one agent works better than another. They are the most potent inhibitors of acid secretion available. PPIs are among the most widely sold drugs in the world, and the first one, omeprazole, is on the WHO Model List of Essential Medicines. Cost varies significantly between different agents. Proton Pump Inhibitors are used to relieve symptoms of Gastroesophageal reflux disease (GERD) or acid reflux. This is a condition in which food or liquid moves up from the stomach to the esophagus (the tube from the mouth to the stomach). PPIs are also used to treat stomach ulcer, a duodenal, or damage to the lower esophagus caused by acid reflux. There are many names and brands of Proton Pump Inhibitors. Most of them work equally as well. Side effects may vary from drug to drug. Some of the PPIs are; Omeprazole (Prilosec), also available over-the-counter (without a prescription), Esomeprazole (Nexium), also available over-the-counter (without a prescription), Lansoprazole (Prevacid), Rabeprazole (AcipHex), Pantoprazole (Protonix), Dexlansoprazole (Dexilant), Zegerid (omeprazole with sodium bicarbonate), also available over-the-counter (without a prescription).